Elastomer spring especially for rail vehicles

ABSTRACT

An elastomer spring, particularly for rail vehicles, comprises a core made of metal or plastic; an outer sleeve that also consists of metal or plastic; a cushion made of elastomer material, in the form of a layered spring that is arranged between the core and the outer sleeve; as well as a base chamber that is configured below a core offset. The elastomer spring is configured in multiple steps in the vertical direction X, specifically consisting of at least a first spring and a second spring, whereby a chamber is present between two springs, in each instance.

CROSS REFERENCE TO RELATED APPLICATIONS

Applicants claim priority under 35 U.S.C. §119 of German Application No.102 26 166.0 filed on Jun. 12, 2002. Applicants also claim priorityunder 35 U.S.C. §365 of PCT/DE03/01682 filed on May 24, 2003. Theinternational application under PCT article 21(2) was not published inEnglish.

The invention relates to an elastomer spring, particularly for railvehicles, comprising at least:

-   -   a core made of metal or plastic (e.g. on the basis of        polyphenylene ether);    -   an outer sleeve that also consists of metal or plastic;    -   a cushion made of elastomer material, in the form of a layered        spring (e.g. metal/elastomer laminate) that is arranged between        the core and the outer sleeve; as well as    -   a base chamber that is configured below a core offset.

An elastomer spring of this type, which is described, for example, inthe document DE 295 20 881 U1, is preferably used in rail vehicletechnology, and will now be explained in greater detail below.

A significant aspect is the guidance of the wheel set of a rail vehicleby means of elastic, play-free elastomer springs, in linear manner, inthe three spatial directions, whereby the elastomer spring is attachedbetween the frame of the rail vehicle and the axle bearing. In thisconnection, the lengthwise and crosswise axes of the vehicle lie in theradial direction of the guide element, while the vehicle axis runs inthe axial direction of the latter.

The main requirement consists of optimization of the springcharacteristic in the vertical direction, in order to guaranteeprotection against derailment when the vehicle is in the unloaded state,and to nevertheless fulfill the spring requirements when the vehicle isloaded. The desired ratio of the vertical stiffness in the unloadedstate to that in the loaded state is generally approximately 0.2:1 to0.8:1.

In the case of a conventional elastomer spring, the vertical springcharacteristic generally runs in linear manner between the unloaded andthe loaded state, in other words the stiffness ratio is 1:1 which, inthe unloaded state can have the result that there is no guarantee thatderailment will not occur. Therefore a compromise has to be made betweenthe vertical stiffness of the two load states.

The task of the invention now consists of making available an elastomerspring that fulfills the entire complex of requirements indicated above.

This task is accomplished according to the characterizing part of claim1, in that the elastomer spring is configured in multiple steps in thevertical direction, specifically consisting of at least a first springand a second spring, whereby a chamber is present between two springs,in each instance.

Practical embodiments of the invention are named in claims 2 to 3.

By means of the configuration of the equalization bores, according toclaim 5 or 6, and the use of throttles that can be controlled orregulated, according to claim 7, defined damping can additionally beachieved. It is furthermore possible to increase this damping in thatthe enclosed air volumes are replaced with a suitable damping fluid.

By means of the active application of compressed air or a pressurizedfluid to the inside of the spring, it is possible to achieve activesupport of the elastomer spring. In this way, level regulation isadditionally possible, as is the adaptation of the load-dependentvertical spring characteristic.

The invention will now be explained using exemplary embodiments, makingreference to the drawings. These show:

FIG. 1 a two-stage elastomer spring having a cushion of elastomermaterial as well as a system of equalization bores;

FIG. 2 a two-stage elastomer spring having a cushion in the form of alayered spring as well as a system of equalization bores.

The elastomer spring 1 according to FIG. 1 consists, in the verticaldirection, of a first spring I and a second spring II, each of whichcomprises a core 2, an outer sleeve 3, and a cushion 3 made of elastomermaterial. The cushion generally possesses a slanted shoulder design. Inthis connection, the core and the outer sleeve have cone surfaces 5 and6, respectively, which correspond with the cushion and adhere to it.Each spring is joined together as a single component, specifically bymeans of a plug-in groove system 8 and 9, respectively, of the corecomponents and the outer sleeve components. When the core components arejoined together, an equalization bore A assures ventilation.

A chamber 7 is present between the two springs I and II, at a distance Lof the vertical clearances of 15 to 45 mm, which chamber extendscontinuously from the core to the outer sleeve. In addition, theelastomer spring is provided with a base chamber 11, which is formedbelow a core offset H with reference to the outer sleeve bottom, and hasa sealing plate 10 at its bottom.

In the following, two chamber variants will now be presented:

-   -   The chamber 7 and the base chamber 11 are configured as air        chambers, whereby the two equalization bores B and C ensure that        the individual air volumes can balance out. If necessary, the        equalization bore B can be combined with a throttle that can be        controlled or regulated.    -   The chamber 7 and the base chamber 11 are filled with a damping        fluid, which is glycol, in particular. Here, the equalization        bore B is combined with a throttle that can be controlled or        regulated, while the equalization bore C has the function of an        overflow channel between the chamber 7 and the base chamber 11,        within the core 2 of the spring I.

FIG. 2 shows an elastomer spring 12, the cushion 13 of which is alayered spring in the form of a metal/elastomer laminate. The metalparts can also be replaced by a corresponding plastic, for example onthe basis of polyphenylene ether.

The plug-in groove system 14 of the core components is provided with aglide system 15 here, for example in the form of glide bushings. Thecore 2 of the spring I has two equalization bores D and F. In thisconnection, the equalization bore D takes over venting of the groove ofthe plug-in groove system when the spring I and II are joined togetherin the case of a chamber 7 and a base chamber 11 filled with air. If thetwo chambers 7 and 11 as well as the groove of the plug-in groove systemare filled with a damping fluid, the equalization bore D has thefunction of an overflow channel.

The same aspects as those already described within the framework of FIG.1 apply with regard to the equalization bores E and F.

The core components and sleeve components as well as the layercomponents of the cushion 13 have concave or convex surfaces.

The core component of the spring II is usually provided with anattachment system 16.

The principle of a state of two stages as shown in FIGS. 1 and 2 canalso be applied to a state of three stages or multiple stages, wherebythe measures of claims 2 to 3 can be used. In most cases, however, anelastomer spring having two stages is sufficient with regard to thestatement of task.

Even though the measure according to claim 2 is an advantageousconfiguration of the multi-stage elastomer spring, the sealing plate 10can be eliminated, specifically with the formation of a base chamber 11that is then open on the bottom, which does not communicate with thechamber 7. In this regard, reference is made to the document DE 295 20881 U1 that was mentioned initially.

REFERENCE SYMBOL LIST

-   1 elastomer spring-   2 core-   3 outer sleeve-   4 cushion-   5 cone surfaces of the core-   6 cone surfaces of the outer sleeve-   7 chamber-   8 plug-in groove system of the core-   9 plug-in groove system of the outer sleeve-   10 sealing plate-   11 base chamber-   12 elastomer spring-   13 cushion (layered spring)-   14 plug-in groove system of the core-   15 glide system-   16 attachment system-   I first spring (bearing)-   II second spring (bearing)-   X vertical direction-   L distance between the vertical clearances-   A equalization bore-   B equalization bore-   C equalization bore-   D equalization bore-   E equalization bore-   F equalization bore-   H core offset

1. Elastomer spring (1, 12), comprising at least: a core (2) made ofmetal or plastic; an outer sleeve (3) that also consists of metal orplastic; a cushion (4, 13) made of elastomer material, in the form of alayered spring that is arranged between the core (2) and the outersleeve (3); as well as a base chamber (11) that is configured below acore offset (H), wherein the elastomer spring (1, 12) is configured inmultiple steps in the vertical direction X, consisting of at least afirst spring (I) and a second spring (II), whereby a chamber (7) ispresent between two springs, in each instance and wherein each spring(I, II) is joined together as individual components, and the chamber (7)between two springs extends continuoustly from the core (2) to the outersleeve (3) and wherein individual components are joined together bymeans of a plug-in groove system (8, 9, 14) of core components and outersleeve components.
 2. Elastomer spring according to claim 1, whereinbase chamber (11) is provided with a sealing plate (10) on the bottom,and wherein the base chamber communicates with the chamber (7) betweentwo springs (I, II).
 3. Elastomer spring according to claim 1, whereinthe plug-in groove system (14) of the core components is provided with aglide system (15).
 4. Elastomer spring according to claim 1, wherein adistance L between vertical clearances between the first and the secondspring (I, II) is 15 to 45 mm.
 5. Elastomer spring according to claim 1,wherein the chamber (7) between two springs (I, II) is provided with atleast one equalization bore (A, B, C, D, E, F).
 6. Elastomer springaccording to claim 5, wherein the equalization bore (A, B, C, D, E, F)runs within the core (2) and/or the outer sleeve (3).
 7. Elastomerspring according to claim 5 wherein the equalization bore (B, E) iscombined with a throttle that can be controlled or regulated. 8.Elastomer spring according to claim 1, wherein the chamber (7) betweentwo springs (I, II) is configured as an air chamber.
 9. Elastomer springaccording to claim 1, wherein the chamber (7) between two springs (I,II) is filled with a damping fluid.
 10. Elastomer spring according toclaim 9, wherein the damping fluid is a multivalent alcohol,particularly glycol.
 11. Elastomer spring according to claim 1, whereinthe core (2) and/or the outer sleeve (3) have cone surfaces (5, 6),concave and/or convex surfaces, which correspond to the cushion (4, 13).